Methods of treating tobacco



Aug. 30,'1955' W HA E 2,716,411

METHODS OF TREATING TOBACCO Filed March 1, 1950 INVENTOR. WiLLiam J Ha Le ATTOENE Y United States PatentO METHODS OF TREATING TOBACCO William J. Hale, Midland, Mich., assignor to Ve rdurin Company, Detroit, Mich., a corporation of Michigan Application March 1, 1950, Serial No. 147,159

12 Claims. (Cl. 13l9) This invention pertains to methods of treating tobacco and improved tobacco smoking compositions and relates to improvements in the process and product disclosed in U. S. Patents 2,460,284 and 2,460,285 to W. J. Hale. In such patents it was disclosed that when cured tobacco and paper wrapping of tobacco, respectively, are impregnated with solubilized chlorophyll or related compounds, the finished product in the process of smoking undergoes a more complete burning by reason of the catalytic effect of the chlorophyll.

The mechanism of this marked step-up in oxidation for both tobacco and wrapper involves the evolution of nascent oxygen from that component known as chlorophyll-b whereby such activated oxygen immediately destroys the acrid vapors carried in the smoke passing over the chlorophyll. When chlorophyll-b is thus deprived of its lightly bound oxygen it reverts to chlorophyll-a and again functions to take up a new portion of atmospheric oxygen whereby to reform chlorophyll-b. This process of oxidation-reduction continues till the close approach of the fire zone of burning tobacco when all is destroyed. Besides chlorophyll-a and chlorophyll-b, a number of derivatives, comprehended under the broad term porphyrins, are equally as serviceable. Notably here are to be included magnesium-free chlorophyll or pheophytin-a and pheophytin-b, and its hydrolyzed or water-soluble form, pheophorbide-a and pheophorbide-b. In general there is included still other porphyrins carrying a S-membered carbocyclic ring at positions 6 and gamma; such compounds are known as phorbins and display a remarkable oxygenative-reductive equilibrium so characteristic of chlorophyll itself.

It has recently been ascertained that the most completely destroyed component in the acrid vapors issuing from chlorophyllized tobacco and wrapper is acrolein (CH2:CH.CHO). This highly pungent compound is always produced in the incomplete combustion of paper, or cellulose, comprising the whole of cigarette wrapper and most of tobacco leaf wrapper as well as the greater portion of tobacco itself. In pure oxygen, of course, these products burn to completion i. e. chiefly to carbon dioxide and water. However, when chlorophyll derivatives are present in tobacco and wrapper in catalytic proportions i. e. less than approximately 2% of total weight, no trace of this deleterious aldehyde can be detected and hence there occurs less rasping effect of the smoke upon the lining membrane of the throat of a smoker.

Heretofore, no'matter what, the amount of oxidizing adjuvants in tobacco the burning of cigarette paper alone gives rise to so great a quantity of acrolein as to escape largely these adjuvants by speedy passage through the cigarette to appear in the smokers mouth. Hence present-day cigarettes, to a greater or less extent, are irritating both to the eyes and to the throat of the smoker. The introduction of chlorophyll derivatives'into paper wrapper of cigarette ensures complete combustion of said paper and thereby dispels any trace of acrolein arising from wrapper. tributes to a better burning of both tobacco and wrapper.

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this quarter. The same general result is likewise found when tobacco carrying chlorophyll derivatives is subjected to burning. All of this is readily demonstrable as, for example, by holding the lighted. end of a cigarette carrying chlorophyll derivatives at a position 4 or 5 inches beneath the wide open eyes when no smarting sensation on eyes is detectable. On the other hand, smoke from the lighted end of a cigarette not so treated is exceedingly smarting to the eyes.

By reason of the greater ease with which the more volatile acrolein and aldehydes of lower molecular weight such as formaldehyde and acetaldehyde are oxidized in the presence of the catalyst chlorophyll or its derivatives, it is not apparent that chlorophyllized cigarettes are definitely less iritating to throat, lungs and nasal passages of the smoker. In keeping therewith, highly noxious aldehydes are denied entrance to lungs and hence the establishment of irritation points, so prevalent among heavy cigarette smokers, may be considerably minimized.

In confirmation of the above it is to be noted that cigar wrappers cured in deep shade exhibit tiny green patches indicative of remnants of chlorophyll and often to as much as of 1 per cent of the weight of the Consequently this trace of chlorophyll con- But for complete destruction of acrolein and the more volatile undersirable aldehydes it is necessary to treat cigar filler tobacco as well as the leaf wrapper with chlorophyll derivatives.

On the other hand, it is to be noted that nicotine and its congenersin chlorophyllized cigarettes and cigars suffer little or no oxidation. This is due to the far greater tendency to oxidation displayed by aldehydes of low molecular weight in consuming the total supply of activated oxygen available. In like fashion the quantity of toxic carbon monoxide, which may amount to several cubic centimeters volume in the smoke from a single cigarette, is simultaneously reduced through the more speedy oxidation of these lower aldehydes and to as much as over half its usual content. As a result the aroma and taste of the cigarette smoke remains unimpaired. Chlorophyllized cigarettes, therefore, are definitely distinguished for their mildness but particularly for a sweetness beyond all degrees of mildness.

. To the attainment of ends sought, it was early learned that only a solubilized chlorophyll derivative, or oxygenative porphyrin, could be made to serve effectively. This soluble form, as shown in patents above cited, embraces an alcoholic or nearly anhydrous solution of ordinary insoluble chlorophyll as derived directly from flora as well as a water solution of hydrolyzed chlorophyll, a chlorophyll deprived of phytyl and methyl groups .through replacement with alkali metals and known specifically as chlorophyllin.

Such chlorophyllins are read-, ily soluble in water thereby affording a simple means of intimately contacting this active agent with both tobacco and wrapper. The presence of those naturally occurring concomitants of chlorophyll, thecarotenoids, likewise may be retained in these solutions for the purpose of serving as stabilizers to the chlorophyll derivatives.

' It has now been discovered that though catalytic quantities of the water-insoluble, unhydrolyzed chlorophyll within tobacco and wrapper impart no bitterness to lips and tongue of the smoker, an entirely different and undesirable'unpleasantness accrues to the smoker when use is made of water-soluble chlorophyll and phorbins generally. This evidently is due to the powerful detergent and penetrating property of of chlorophyll derivatives, naturally bitter to taste, on coming in contact -with the saliva of the mouth.

To obviate this somewhat puckering after-taste it would 3 seem that the use of a cork or other tip to cigarette or cigar might be effective. Experience proved otherwise. The water-soluble chlorophyll derivative carried in the tobacco was just as penetrative as before. Hence there remained two definite courses; either to interpose a filter between cigarette and smoker and similarly resort to a cigar holder or to destroy the chlorophyll contiguous to the smokers lips, i. e., at each end of the cigarette or cigar. The present invention involves this latter approach and relates to a method of destroying the chlorophyll at the tip or end of the cigarette or cigar which contacts the lips of the smoker so that during smoking even though such end be somewhat wetted with saliva, no chlorophyll can contact the lips or tongue.

The mechanism utilized for carrying out the invention may take a variety of forms, one illustrative embodiment of which is shown in the accompanying drawings in which Fig. 1 is a diagrammatic illustration of a cigarette treated according to the invention.

Fig. 2 is a similar view of a cigar similarly treated to destroy or inactivate the chlorophyll in the tip or mouth-engaging section of the cigar, and

Fig. 3 is a diagrammatic illustration of an apparatus which may be employed for carrying out the invention.

As shown in Fig. 3, the apparatus for effectively carrying out the invention may comprise essentially the trough or channel 1 composed of metal or other suitable material of construction. This is finished with a glass, plastic or other light permeable window or tube 2. Suitably spaced from the Window 2 is a source of an electromagnetic energy such as a plurality of infrared or ultraviolet lamp 3 suitably positioned about or around the window 2 so as to completely irradiate the tip end of the cigarette or cigar. This as indicated may comprise a parabolic mirror or reflector 4 provided with an emitter element 5 radiations from which are concentrated by the parabolic mirror or reflector 6 through the Window 2 on the tip end of the cigarette (or cigar) 7. The electrical circuit to which the emitter 3 is connected, may be controlled by suitable trip and switch mechanism, such as properly designed micro switches such that as the cigarette or cigar units are continuously conveyed through the trough or channel 1 the tip end of the cigarette or cigar is subjected to irradiation from the lamp 3 for a sulficient period of time to destroy or inactivate the chlorophyll in the mouth engaging end 8 of the cigarette or the mouth engaging end 9 of the cigar 10. With suitable electrical controls the cigarettes and/or cigars can be passed in an intermittent or step-wise passage through the channel 1 with a dwell or retention period under the irradiations from lamp 3 suflicient to substantially or completely inactivate the chlorophyll in the irradiated zone of the cigarette or cigar.

Such destruction of the soluble chlorophyll in the end or lip-contacting zone of the cigar or cigarette may be achieved by several methods. It has been ascertained that by subjecting the tobacco and paper at the end of the cigarette to the action of electromagnetic radiation under properly controlled conditions, the chlorophyll incorporated in the cigarette at such end may readily be destroyed. Thus within the concept of the invention light waves and heat waves may be utilized for this chlorophyll destruction in the selected zone or end of the cigarette. It has been found that ultraviolet light and more especially infrared radiation are most effective for the purposes of the invention. Chlorophyll is particularly sensitive to infrared rays.

As a result of considerable experimentation and test, it has been found practical to submit the ends of cigarettes and cigars, carrying the water soluble chlorophyll, to exposure to infrared radiation for but a very brief period of time to achieve the desired results. In actual operation the cigarettes, for example, may be passed continuously through or along a trough or channel, one

.rnouth-contacting ends.

4 side wall of which is composed of a material which permits the transmission of the rays and in effect constitutes a window. As the cigarettes pass along such channel, with the ends adjacent the side walls, one end is subjected to the radiations such as infrared radiations generated by lamps placed near the window.

It has been found that if the chlorophyll at the end of the cigarette is destroyed to a distance of from about one-tenth to about one-fifth the length of the cigarette, a dechlorophyllized tip results and the possibility of wetting the lips or tongue with the astringent and bitter water soluble chlorophyll is eliminated. With effective infrared ray lamps this period of treatment is quite brief, extending only a matter of seconds.

It is to be noted at this point that the described irradiation treatment results in a marked darkening of the tobacco in the irradiated zone. This darkening thus provides a quick means of determining the proper length of time for the irradiation for with a few tests with a particular installation the length of the dechlorophyllized zone can quickly be correlated with the time of exposure to the electromagnetic radiations used.

It is to be observed, as noted above, that the dechlorophyllized zone constitutes only a minor portion of the length of the cigarette, preferably about one-third of an inch and hence in the remainder of the cigarette there is an abundant supply of the active chlorophyll derivative to function catalytically, in the manner described to destroy undesirable acrid vapors.

Since, as explained, the irradiation treatment considerably darkens the tobacco in the end treated, this darkened end thus optically indicates the end of the cigarettes -which should be placed in the month. However, in

order to insure the advantages of the invention without requiring inspection by the smoker to choose the proper end, it may be desirable to irradiate each end of the cigarette to .destroy the astringent chlorophyll in the This, of course, may readily be done by forming each side wall of the channel or trough of material which does not filter or materially block the passage of the radiations and subjecting each end of the cigarettes to action of the radiations employed.

As previously stated, ordinary chlorophyll of insoluble characteristics is not bitter to the taste till it is hydrolyzed or made water soluble.

It has further been found that cigarettes carrying water soluble chlorophyll derivatives when made to carry a cork, paper or other tip, as well as cigars rolled to closed point for holding in the mouth, have no need of subjection to electromagnetic radiation save on the end intended for insertion into the mouth. The tip of the cigarette and closed wrapper of the cigar point do not substantially interfere with the penetration of the cigar or cigarette radiant energy.

It is to be understood that the irradiation of the tip or ends of the cigarette may be carried out at any convenient stage in the cigarette producing process. While, in the illustrative embodiment of the process this irradiation treatment is described as being applied to the loose cigarettes as they travel along a trough or channel, it will be appreciated that the irradiation can be effected on groups of cigarettes during any intermediate stage of packaging just so long as the package does not contain a wrapping, such as a metallic foil, which would seriously retard the transmission of the radiation utilized.

While a preferred modification of the invention has been described, it is to be understood that this is given didactically to illustrate the underlying principles involved and not as limiting the useful scope of the invention to such illustrative embodiment.

I claim:

1. As an article of manufacture, a cigarette having incorporated active water soluble chlorophyll in both the tobacco and paper wrapper thereof throughout the major portion of its length but being substantially free from such chlorophyll at one end of the cigarette.

2. As an article of manufacture, a cigarette having incorporated in the tobacco a quantity of active water soluble chlorophyll throughout the major portion of its length but being free from such chlorophyll at the mouthcontacting end of the cigarette.

3. As an article of manufacture, a cigarette of which the paper wrapper contains a quantity of water soluble chlorophyll for the major portion of its length but which is free from said chlorophyll at the mouth-contacting end thereof.

4. As an article of manufacture, a wrapper-enclosed I roll of tobacco having an amount of water-soluble oxygenative porphyrin in both the tobacco and wrapper to enhance smoking qualities thereof, the amount of oxygenative porphyrin not exceeding substantially 2% on the dry weight of tobacco, and both ends of tobacco roll having said oxygenative porphyrin destroyed to the extent of approximately $5 to $3 the length of tobacco roll thereby to eliminate bitterness to taste of end of roll in coming in contact with lips of smoker.

5. As an article of manufacture, a wrapper-enclosed roll of tobacco having an amount of water-soluble chlorophyll derivative in both the tobacco and wrapper to enhance smoking qualities thereof, the amount of chlorophyll derivative not exceeding substantially 2% on the dry weight of tobacco, and both ends of tobacco roll having said chlorophyll derivative destroyed to the extent of approximately A to ,6 the length of tobacco roll thereby to eliminate bitterness to taste of end of roll in coming in contact with lips of smoker.

6. As an article of manufacture, a wrapper-enclosed roll of tobacco having an amount of water-soluble pheophorbide in both the tobacco and wrapper to enhance smoking qualities thereof, the amount of pheophorbide not exceeding substantially 2% 0n the dry weight of tobacco, and both ends of tobacco roll having said pheophorbide destroyed to the extent of approximately bi to 3% the length of tobacco roll thereby to eliminate bitterness to taste of end of roll in coming in contact with lips of smoker.

7. A method of enhancing the smoking quality of cigarettes which comprises impregnating the tobacco and wrapper with a water solution containing an oxygenative porphyrin in catalytic amounts of between .01% and 2% of the dry weight of tobacco and wrapper, and briefly subjecting both ends of the cigarette to the action of electromagnetic radiation to destroy porphyrin for a distance approximately $5 to Vs the length of the cigarette thereby to eliminate bitterness to the taste of the cigarette in coming in contact with the lips of the smoker.

8. A method of enhancing the smoking quality of cigarettes which comprises impregnating the tobacco and wrapper with a water solution containing a water-soluble chlorophyll derivative in catalytic amounts of between .0l% and 2% of the dry weight of tobacco and wrapper, and briefly subjecting both ends of the cigarette to the action of electromagnetic radiation to destroy the chlorophyll for a distance approximately $4 to /s the length of the cigarette thereby to eliminate bitterness to the taste of the cigarette in coming in contact with the lips of the smoker.

9. A method of enhancing the smoking quality of cigarettes which comprises impregnating the tobacco and wrapper with a water solution containing a water-soluble pheophorbide in catalytic amounts of between .01% and 2% of the dry weight of tobacco and wrapper, and briefly subjecting both ends of the cigarette to the action of electromagnetic radiation to destroy the pheophorbide for a distance approximately $5 to V5 the length of the cigarette thereby to eliminate bitterness to the taste of the cigarette in coming in contact with the lips of the smoker.

10. As an article of manufacture, a cigarette having incorporated in both tobacco and wrapper an amount of water-soluble chlorophyll approximately M to /2 of 1% of the dry weight of the tobacco and wrapper together with approximately one-fifth this amount of carotenoids and the not-to-be-lighted end being free from such chlorophyll over an extent approximating A to /5 the length of the cigarette.

11. As an article of manufacture, a cigarette having incorporated in both tobacco and wrapper an amount of water-soluble pheophorbide approximately 1 to /2 of 1% of the dry weight of the tobacco and wrapper together with approximately one-fifth this amount of caro-,

tenoids and in which the not-to-be-lighted end the chlorophyll is destroyed over an extent approximating A to /s the length of the cigarette.

12. As an article of manufacture, a cigar having incorporated in both tobacco and wrapper an amount of watersoluble chlorophyll approximately ,5 to /2 of 1% of the dry weight of the tobacco and wrapper together with approximately one-fifth this amount of carotenoids and the not-to-be-lighted end being free from such chlorophyll over an extent approximating A to V5 the length of the cigar.

References Cited in the file of this patent UNITED STATES PATENTS 1,902,775 Herrmann Mar. 21, 1933 2,460,284 Hale Feb. 1, 1949 2,460,285 Hale Feb. 1, 1949 

1. AS AN ARTICLE OF MANUFACTURE, A CIGARETTE HAVING INCORPORATED ACTIVE WATER SOLUBLE CHLOROPHYLL IN BOTH THE TOBACCO AND PAPER WRAPPER THEREOF THROUGHOUT THE MAJOR PORTION OF ITS LENGTH BUT BEING SUBSTANTIALLY FREE FROM SUCH CHLOROPHYLL AT ONE END OF THE CIGARETTE. 